Automatic fuel control device for internal combustion engines



Feb. 9, 1932. w. R. PULKINGHORN AUTOMATIC FUEL CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Jan. 21. 1931 Patented Feb. 9, 1932 UNITED STATES PATENT oFFica WILLIAM `Ross PULKLNGHORN, oF HOLLYWOOD, CALIFORNIA, AssIGNoR or ONE-HALF 'ro JOSEPH s. DAVIS, or Los ANGELES, CALIFORNIA AUTOMATIC FUEL CONTROL DEVICE FOB, INTERNAL COMBSTION' ENGINES Application led January 21, 1931. Serial No. 510,142.

This invention relates to a gaseous or vaporized fuel control device adapted to be. connected to the intake manifold or incorporated with the carburetor' of an internal combus-V tion engine, more particularly to the engines of motor vehicles.

Should the accelerator throttle valveI be suddenly closedwhile the engine is rotating under the above conditions a degree of vacuum cylinders.

is created in the intake manifold due to reducing vor checking the supply of gaseous mixture from the carburetor to the engine Should the above stated condition exist for any length of time, i. e., while the vehicle is coasting down grade ory between traffic intersections with the gears in mesh and the clutch engaged, or between ear lshifts when the engine is speeded up an the accelerator throt tle suddenly closed, the intake manifold, cylinders and exhaust manifold become filled with un'burnt gaseous fuel due to insuicient compression,- and lack of time for proper combustion. f v

The accumulation of unburnt fuel thus formed is suddenly expelled through the exhaust during the coasting period and when the throttle is again opened or upon a return to idling of the engine. This discharge of unburnt fuel into the atmosphere is`not only very obnoxious to occupants 0f thevehicle and others within its range, but results ina loss of fuel which although imperceptible during each of theabove stated intervals amounts to considerable when taken collectively, also the unburnt fuel works past the pistons into the crank case resulting in a dilution of the lubricating oil therein causing increased engine Wear.

The object of this invention is to provide a device of the character referred to which will autfrnatically cut olf the fuel supply to an internal combustion engine should the accelerator throttle valve be closed while the engine is rotating faster than the` so-Icalled idling speed and thereby prevent any vaporized fuel from the carburetor entering the engine until the accelerator throttle valve is again opened or upon a return to idling speed.

It is also understood that during the operation of an internal combustion engine Iwhen the accelerator throttle valve is opened, after the engine has been running at idlin speed, or upon a `return to idling speed after the engine has been running faster than idling speed with the accelerator throttle valve closed, the degree of vacuum is at the lowest point.

It is, therefore, another object of the resent invention to provide means where y a charge of fuel may be introduced into the intake manifold of an internal combustion engine-independently of the suction andoperable only when the suction is reduced below normal operating conditions in order that the engine will not stall for lack of fueL Other objects and advantages will be apparent from the following description, reference being had to the accompanying drawings, in whichi F'g. 1 is a side elevation of an internal combustion v engine showing the automatic fuel control device connected to the intake manifold.

F ig. 2- is a longitudinal section taken through the fuel control device.

Fig. 3 is a fragmentary detail section taken on line 3-3 of Fig. 2.

Referring more specifically to the drawings, 10 designates a. conventional internal combustion engine, including a carburetor 11,

intake manifold 12, and exhaust manifold 13.

The improved gaseous fuel control device generallyr designated at'1'4 is adapted to be connected to the intake manifold as shown 'DiP chamber 49 formed in the body member with speed, hence the accelerator throttle valve designated at 16 should be adjusted, also the v usual idling orts` therein closed or plu yged so that it w' entirely cut oil the fuel rom the carburetor when it is closed. The needle valve of the main carburetor should also be adjusted to compensate for the fuel admitted through the auxiliary carburetor of the dcvice when the accelerator throttle is opened.

Referring more specifically to Fig. 2, 18 designates a body member or casting having an internally threaded boss 19 formed on its bottom face into which is screw threaded a usual coupling or union 20 including a nipple 21 adapted to be screw threaded into an opening formed in the intake manifold.

Liquid fuel is .fed into the device from the usual reservoir or vacuum tank (not shown) through a pipe line 22 which is connected by avunion to an inlet litting 23 preferably rovided with a filtering screen 24, the uid passing throu h the screen thence through ports 25 forme in a member 26 having a bore 27 normally closed by a float valve 28 when the engine is not running.

Float valve 28 is connected by a rocker arm 29 to a float 30 disposed in a chamber 31 formed iu the body member 18, fluid F in the float chamber passes through a port 32 controlled by a needle valve 33 into a reservoir 34 through a port 35, the fluid seeking a level in the float chamber and reservoir.

Mounted in the upper end of the reservoir is a primary air admission tube 36 or regulator which registers with dport 37 communieating with a va orizer or mixing tube generally designate at 38. The mixing tube or vaporizer 38 consists of a tubular member 39 screw threaded into the4 upper end of a recess 40, and is provided with a tapered bore 41 in which is concentrically disposed an adjustable air admission tube 42 having an externallytapered face.

The above described parts operate in exact-ly the same manner as a usual carburetor, and serve to admit fuel to the engine during idling speed, it being necessary that the accelerator valve be closed in order that the device will perform its intended functions in a manner more fully hereinafterv described. It being particularly noted that due to inde` pendent adjustment and relatively small diameter of the mixin or vaporizing tube the idling mixture may very accurately controlled, resulting in smoother running of the Yengine at idling speed than is possible to attain with the usual or main carburetor. The mixture from the idling jet or vaporizer passes through a port 43 into an annular recess 44 formed in the body member, ports v45 into a bore 46 formed in the center member 47 of a diaphragm 48 thence into the'` intake manifoldthrough the coupling member 20.

` 48 is mounted in an annular its bottom face engaging a washer 50g-and is held in place by a nut 51 screw threaded on the portion 52 of the center member projecting through an openin below the recess 44. lidably mounted in t e center member and adjustably secured to the head 53 of the diaphragm is a stem 54 having a tapered valve 55 formed on its lower end which is adapted to engage a seat 56 formed in its lower end when the diaphragm is distended. Mounted in a recess 60 formed in the body member is a valve member 61 consisting of a tubular housing 62 having a ta red seat 63 formed in its lower end, and sliibly mounted in said housing is a valve 64 normally urged into engagement with the seat by an expansion coil spring 65. The tension of said spring bein -regulated by an adjusting screw 66 threade threaded into the upper end of the housing. The tubular housing 62 extends through an in sleeve 66a which in turn is4 opening 67 of lar er diameter formed in a cover or closure .p ate 68 removably secured to the body member, the housing having a shoulder 69 engaging a 'ring' o r gasket 70 closing the upper end of the opening 67.

Screw threaded into a recess 71 formed in the body member is a second valve member generally designated at 72 consisting of a housing 73 in which is slidably mounted a valve 74 having a tapered .end l75 adapted to engage a seat 76 formed in the lower end of the housing. The valve 74 is normally held out of engagement with the seat by a coil spring 77 connected thereto andto a stem 78 vupon which is threaded a nut 79 engaging the uplper end of al fitting 80 screw threade into t rotation by tongues 81 thereon dis osed in grooves 81a formed in the fitting. t being understood that the valves 64 and 74 should be adjusted according to the piston displacement of the engine to 'which each device is ap lied so that they will operate properly.

suction created in the intake manifold communicates with a chamber 82 (formed in the body member) through a port 83, and mounted in the chamber is a diaphragm 84 which serves toxintroduce a charge of fluid into the intake manifold to aid in starting or prevent stalling of the engine upon opening of the accelerator throttle valve after it has been closed when the engine is rotating V faster than idlin speed.

Operation: ssuming theaccelerator throttle valve is opened a circulation of air passes throu h ports 85 formed in the fitting 80 of the valve member 72, valve 74 into the recess 71 (t e valve 74 being held open by the spring 77) thence through a'port 87 into the chamber 49. The

circulation continues through the chamber 49, port 88, valve seat 63, rts'89 formed in the valve 64 (said valve t i n being unseated against the action of the spring 65), ports 90 orts 86 in thee housing, the -stem being held against formed in the housing 62 of the valve member 61 into the opening 67 formed inthe cover 68, intothe chamber 83 through ports 91 formed in the cover 68, thence through the chamber 82 and port 83 into the inta c manifold.

During the time the acceleratorthrottle is opened a limited amount of vaporized fuel also enters the intake manifold.

Upon closing of the accelerator throttle the carburetor of the device functions to furnish fuel during the so-called idling speed. On the other hand should the accelerator throttle be suddenly closed while the engine is rotating faster than idling speed the vacuum created in the intake manifold will tend to exhaust or withdraw air normally circulating -through the valve members, chambers and ports above described, whereupon the valve 64 is fully nnseated and the valve 74 seated resulting in creating a vacuum in the chamber 49, which in turn causes the valve 55 to seat due to distention ot the diaphragm 48, thus simultaneously cutting otl' the idling fuel supply and any further circulation of air through the valve members 61 and 72. It being understood that atmospheric pressure exerted on the interior of the diaphragm through a port 92 (see Fig. 3) actually effects closing of the valve 55.

When the accelerator throttle is again opened or upon a return to idling speed the valve 74 is instantly nnseated (due to decreased suction) whereupon the valve 55 is opened by collapsing or returning to normal position of the diaphragm 48, thus restoring the idling mixture.

The device functions as above described except that during gear shifting the valve 48 automatically opens a moment before idling speed with the accelerator valve still closed during coasting with gears in mesh and each time the clutch is disengaged. thus preventing stalling of the engine during such periods.

From the foregoing it will bc seen that as long as the engine is rotating faster than idling speed with the accelerator throttle closed all air or vaporized fuel is entirely cut off from the engine. However. under certain conditions due to sudden reduction in suction when the accelerator throttle is opened the engine has a tendency to stall for lack of fuel. This is prevented by the diaphragm 84 which functions as follows:

During the interval after the accelerator throttle is closed as above described the diaphragm 84 will be distended as indicated b v dotted lines (see Fig. 2) upon opening ot' the accelerator throttle the vacuum will be immediately reduced whereupon said diaphragm will return to normal position resulting in discharging a quant-ity of liquid fuel drawn into its interior during distention through a port lll communicating with the reservoir 34, back through the ort into the intake manifold, this charge of nel servmg to aid in starting of the engine.

From the foregoing it will be seen that the device efectively prevents any fuel entering the engine except when it is required to produce power and during the so-called idling speed thereby preventing an accumu-l lation of unburnt fuel in the engine cylinders, intake and exhaust manifold.

I claim l. 'l`he combination with an internal combustion engine including a carburetor, an accelerator throttle valve and an intake manifold of a device comprising a body member adapted to be connected to the intake manifold of the engine, a gaseous fuel vaporizer carried by said body member adapted to slipply fuel to the engine during idllng speed, a diaphragm mounted in a chamber formed in said body member. a valve. actuated by said diaphragm adapted to cut otl" the fuel from said vaporizer upon closing of the accelerator valve when the engine is rotating faster than idling speed, a valve member carried by said body member having a valve normally seated and in communication with the suction created by the engine and the chamber in which said diaphragm is mounted, and a second valve member carried by said body member having a valve normally nnseated and in communication with the atmosphere and the chamber in which the diaphragm is mounted, whereby upon closing of the accelerator valve the valve of said diaphragm will be seated thereby cutting off the gaseous fuel supply and circulation of air through the dcvice into the engine.

2. The combination with an internal combustion engine including a carburetor. an accelerator throttle valve and an intake manifold of a device comprising a body member adapted to be connected to the intake manifold of the engine, a gaseous fuel vaporizer carried by said body member adapted to supply fuel to the engine during idling speed, a diaphragm mounted in a chamber formed in said body member. said diaphragm including a center member extending into a recess below the bottom face of the diaphragm and through an opening formed in the body member, a valve connected to the head of said diaphragm and slidably mounted in the center member, there heilig a port formed in the body member communicating with the recess` below the diaphragm and the fuel vaporizcr. and ports in the center member above the dia phragm valve, a valve member carried by said body member having a valve normally seated and in communication with the suction created by the engine and thc chamber in which -said diaphragm is mounted, and a second valve member carried by said body member having a valve. normally nnseated and in communication with the atmosphere and the chamber in which the diaphragm is mounted, whereby upon closing of the accelerator throttle valve when the engine is rotating faster than idling speed said first valve will be unseated and the second valve seated whereupon said diaphragm will be distended by atmospheric pressure causing the valve connected thereto to seat thereb cutting olf ply fuel to the engine during i ling speed a diaphragm mounted in a c amber forme in said body member, a valve actuated by sald dia hragm adapted to cut off the fuel from sai vaporizer upon closing of the accelerator throttle valve when the engine is rotating faster than idling s eed, a valve housing mounted in a recess ormed in said body member, a valve slidably mounted in said housing and in communication with the suction created by the engine and the chamber in which said diaphragm is mounted, and a second valve housing mounted in a recess formed in said body member, a valve slidably mounted in said housing normally unseated and in communication with the atmosphere and the chamber in which the diaphragm is mounted, whereby upon closing of the accelerator throttle valve when the engine is rotating faster than idling speed said first valve will be unseated and the second valve seated whereupon said diaphragm will be distended by atmospheric pressure causing the valve connected thereto to seat thereby cutting off' the gaseous fuel su ply from the vaporizer and circulation of a1r through the device into the engine.

4. The combination with an internal combustion engine includingi a carburetor, an accelerator throttle Valve and an intake manifold of a device comprising a body member adapted to be connected to the. intake mani` fold of the engine, a gaseous fuel vaporizer carried by said body member adapted to supply fuel to the engine during idling speed, a diaphragm mounted in a chamber formed in said body member, said diaphragm including a center member extending into a recess below the bottom face of the diaphragm and through an opening formed in the body member, a Valve connected to the head ofsaid diaphragm and slidably mounted in the center member, there being a port formed in the body member communicating with the recess below the diaphragm and the fuel vaporizer, and ports in the center member above the diahpragm valve, a second diahragm mounted in a chamber formed in said dy member, there being a port formed in the body member communicating with the liquid fuel supply of the vaporizer and the interior of said second diaphra m, whereb upon closing of the accelerator t rottle valve when the engine is rotatin faster than idling speed said iii st valve will unseated and the second valve seated whereupon said first diaphragm will be distended by atmos heric pressure causing the valve connected t ereto to scat thereby cutting off the gaseous fuel supply from the vaporizer and circulation of air throu h the device into the engine, said second diap ragm being distended during closing of the accelerator throttle valve when the engine is rotating faster than idlin speed and drawing a charge of the li uid fue thereinto and colla sing when t e accelerator throttle valve 1s o ned and forcing the charge of the fluid t erein through the vaporizer into the intake manifold.

In testimony whereof I affix my signature. WILLIAM ROSS PULKINGHORN.

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